Introduction
MongoDB and PostgreSQL are both excellent databases — but they excel in very different situations. Here's how to choose based on your actual use case.
Data Model
PostgreSQL excels at relational, structured data with complex joins. MongoDB shines with document-oriented data where the schema evolves frequently.
Performance
For write-heavy workloads with flexible schemas, MongoDB's document model is faster. For complex analytical queries with JOINs, PostgreSQL with proper indexing wins.
Scaling
MongoDB has built-in horizontal sharding. PostgreSQL scales vertically well and can scale horizontally with Citus or read replicas.
When to Use MongoDB
Content management, product catalogs, user profiles, real-time analytics, and any scenario where the data shape changes often.
When to Use PostgreSQL
Financial transactions, inventory systems, anything requiring ACID compliance across multiple tables, or complex reporting.